#!/bin/bash

students=(zhangsan lisi wangwu zhaoliu)
s=
t=
echo $s
for stu in ${students[*]}; do
  echo ${stu}
done

echo ================

for ((i = 0; i < ${#students[*]}; i++)); do
  echo ${students[i]}
done
echo ================
#school=bin_zhou_xue_yuan
school="bin:zhou:xue:yuan"
school_a=(${school//:/ })
for i in ${school_a[*]} ; do
    echo ${i}
done

a=1
b=2
c=100
((a++,c=a+b))
c=$((a+b))
echo ${c}

a=12

while ((a>-100)); do
    name
    ((a--))
    sleep 0.4
done

